By default, many of MicroStation's edit tools are found as the top-most entry of the Task Navigator:

In this task list, two sub-lists contain the most relevant tools when editing feature geometry: Modify and Manipulate.

The Manipulate task list (listed at 3 in the task list above) contains tools to copy, modify, scale, rotate, mirror, etc. feature geometry:

Manipulate tools apply to all types of feature geometry: point, line, and polygon.

The Modify task list (listed at 7 in the task list above) contains tools to modify, extend, trim feature geometry, and modify feature geometry vertexes:

Modify tools are typically applied to linear and polygon feature geometry.